What category of drugs exhibit Horizontal Gaze Nystagmus (HGN) and/or Vertical Gaze Nystagmus (VGN)?

The correct choice revolves around the effects that Central Nervous System (CNS) Depressants have on eye movement and function. Drugs within this category, such as alcohol, benzodiazepines, and barbiturates, can impair motor skills and affect coordination. One significant impact of these substances is the potential to cause both Horizontal Gaze Nystagmus (HGN) and Vertical Gaze Nystagmus (VGN).

HGN refers to the involuntary jerking of the eyes as they gaze to the side, while VGN involves the same jerking when looking up or down. The presence of these types of nystagmus in individuals under the influence of CNS depressants is a key indicator for law enforcement and probation officers when assessing someone's impairment. This can be crucial during field sobriety tests, where the observation of eye movements can help determine the influence of such substances.

In contrast, the other categories like Centrally acting Stimulants, Narcotics, and Psychoactive Stimulants typically do not produce these specific eye movement effects in the same manner as CNS Depressants do. Each of these drug types affects the body differently; for instance, stimulants might enhance alertness and disrupt normal sleep patterns but are